lineedit显示数字

可以通过设置lineEdit的inputMask属性来限制只能输入数字，例如：

from PyQt5.QtWidgets import QLineEdit, QWidget, QVBoxLayout, QApplication

app = QApplication([])
window = QWidget()

layout = QVBoxLayout()
lineEdit = QLineEdit()
lineEdit.setInputMask("9999")  # 只能输入四位数字
layout.addWidget(lineEdit)

window.setLayout(layout)
window.show()
app.exec_()

也可以使用正则表达式来限制输入，例如：

from PyQt5.QtWidgets import QLineEdit, QWidget, QVBoxLayout, QApplication
from PyQt5.QtCore import QRegExp
from PyQt5.QtGui import QRegExpValidator

app = QApplication([])
window = QWidget()

layout = QVBoxLayout()
lineEdit = QLineEdit()
regExp = QRegExp("[0-9]*")  # 只能输入数字
validator = QRegExpValidator(regExp)
lineEdit.setValidator(validator)
layout.addWidget(lineEdit)

window.setLayout(layout)
window.show()
app.exec_()